.box{
    height: 300px;
    width: 500px;
    border: 1px solid #ccc;
    margin: 20px auto;
    .section{
        height: 200px;
        background: #eee;
    }
    .section2{
        height: 200px;
        background: #f1f1f1;
    }
    .section3{
        height: 200px;
        width: 600px;
        background: #f1f1f1;
    }
}